1. Field of the Invention:
The present invention is directed to a multi-type pulse-tube refrigerating system.
2. Discussion of the Background:
A conventional refrigerating system having a plurality of cryogenic temperature generating devices is known as disclosed in Japanese Patent Laid-open No. Hei.5(1993)-45014 published in 1993 without examination.
In the foregoing conventional refrigerating system, each of the cryogenic temperature generating devices is a Gifford-MacMahon type one which is provided with a displacer or piston as an essential element in the vicinity of a cold head. Thus, for generating cryogenic temperature at the cold head of each of the devices, each of the pistons is brought into movement, thereby generating vibrations around the refrigerating system.
Such a conventional refrigerating system may not be acceptable to cool specific substances or items such as a scintillation counter of an energy dispersion type X-ray analyzer. The reason is that the scintillation counter has to be free from vibrations or shocks. Accordingly, a need exists for a refrigerating system without the foregoing drawback.